lkml.org 
[lkml]   [2007]   [May]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: PCIE
    Roland Dreier wrote:
    > > I am now wondering whether the usage of MSI would help in this case and
    > > that i should be using enable_msi before request_irq ?
    >
    > MSI interrupts are never shared. So if pci_enable_msi() succeeds, you
    > can be sure that the interrupts you get with that IRQ number are
    > coming from your device.
    >

    i presume then i shouldn't be using IRQF_SHARED, if using MSI.

    Another question would be if the device supports multiple messages, MSIX
    should be used ?
    In such a context, if i request for say more than the messages that i
    need, say i request 16 messages, but use only 1 or 2, that does bear any
    consequences ?

    > But using MSI does not work on all systems, so your driver needs to
    > work with standard (possibly shared) INTx interrupts too. And you
    > should probably provide at least a module flag to disable the use of
    > MSI, to avoid problems on buggy systems.

    I should probably look for CONFIG_PCI_MSI and check whether the system
    supports MSI pci_enable_msi() ?

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-05-26 17:09    [W:0.025 / U:122.652 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site